I worked these out in 2005. I haven't needed to modify them since.
Macronutrients - N P K - nitrogen, Phosphorous, Potassium
Into 2000 ml (2 liters, ie a large soda pop bottle) of distilled water dissolve:
- 61 g (11 teaspoons) Potassium nitrate (KNO3) - "Stump remover" (Source of "N", and "K")
- 5.2 g (1 teaspoons) Potassium monophosphate (KP04) - "Fleet enema" (Source of "K" and "P")
- 10.8 g (2 teaspoons) Magnesium sulphate - (MgSO4) - "Epsom salts" (Source of "Mg")
- 1.8 g (0.3 or 1/3 teaspoon) Potassium sulphate (KSO4) - (Source of "K")
3 times a week add 10 ml for a 20 gallon tank. Or 1-2 ml daily. Or 15 ml twice a week. This will add 30 ppm nitrate a week to a tank with corresponding correct proportions for the other macronutrients.
For a 100 gallon tank simply multiply by 5. For a 10 gallon tank divide by 2 and so on and so forth.
Fe & Trace Elements
- Use 71 grams of Plantex CSM+B Fe+trace mix in one liter of distilled water.
- This gives you one litre of 0.5% iron+trace solution.
- Use 2 cc per 4 gallons. Find a 5cc cap and use that bottle to store it.
- Ie, one capful per 10 gallons. 5 capfuls per 50 gallons.
This will raise the iron by 5ppm.
Do this 2 - 3 times a week, although 1-7 times a week is better than nothing.